Neuroscience basics for LessWrongians

84 ChrisHallquist 26 July 2012 05:10AM

The origins of this article are in my partial transcript of the live June 2011 debate between Robin Hanson and Eliezer Yudkowsky. While I still feel like I don't entirely understand his arguments, a few of his comments about neuroscience made me strongly go, "no, that's not right."

Furthermore, I've noticed that while LessWrong in general seems to be very strong on the psychological or "black box" side of cognitive science, there isn't as much discussion of neuroscience here. This is somewhat understandable. Our current understanding of neuroscience is frustratingly incomplete, and too much journalism on neuroscience is sensationalistic nonsense. However, I think what we do know is worth knowing. (And part of what makes much neuroscience journalism annoying is that it makes a big deal out of things that are totally unsurprising, given what we already know.)

My qualifications to do this: while my degrees are in philosophy, for awhile in undergrad I was a neuroscience major, and ended up taking quite a bit of neuroscience as a result. This means I can assure you that most of what I say here is standard neuroscience which could be found in an introductory textbook like Nichols, Martin, Wallace, & Fuchs' From Neuron to Brain (one of the text books I used as an undergraduate). The only things that might not be totally standard are the conjecture I make about how complex currently-poorly-understood areas of the brain are likely to be, and also some of the points I make in criticism of Eliezer at the end (though I believe these are not a very big jump from current textbook neuroscience.)

One of the main themes of this article will be specialization within the brain. In particular, we know that the brain is divided into specialized areas at the macro level, and we understand some (though not very much) of the micro-level wiring that supports this specialization. It seems likely that each region of the brain has its own micro-level wiring to support its specialized function, and in some regions the wiring is likely to be quite complex.

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The 5-Second Level

111 Eliezer_Yudkowsky 07 May 2011 04:51AM

To develop methods of teaching rationality skills, you need to learn to focus on mental events that occur in 5 seconds or less.  Most of what you want to teach is directly on this level; the rest consists of chaining together skills on this level.

As our first example, let's take the vital rationalist skill, "Be specific."

Even with people who've had moderate amounts of exposure to Less Wrong, a fair amount of my helping them think effectively often consists of my saying, "Can you give me a specific example of that?" or "Can you be more concrete?"

A couple of formative childhood readings that taught me to be specific:

"What is meant by the word red?"
"It's a color."
"What's a color?"
"Why, it's a quality things have."
"What's a quality?"
"Say, what are you trying to do, anyway?"

You have pushed him into the clouds.  If, on the other hand, we habitually go down the abstraction ladder to lower levels of abstraction when we are asked the meaning of a word, we are less likely to get lost in verbal mazes; we will tend to "have our feet on the ground" and know what we are talking about.  This habit displays itself in an answer such as this:

"What is meant by the word red?"
"Well, the next time you see some cars stopped at an intersection, look at the traffic light facing them.  Also, you might go to the fire department and see how their trucks are painted."

-- S. I. Hayakawa, Language in Thought and Action

and:

"Beware, demon!" he intoned hollowly.  "I am not without defenses."
"Oh yeah?  Name three."

-- Robert Asprin, Another Fine Myth

And now, no sooner does someone tell me that they want to "facilitate communications between managers and employees" than I say, "Can you give me a concrete example of how you would do that?"  Hayakawa taught me to distinguish the concrete and the abstract; and from that small passage in Asprin, I picked up the dreadful personal habit of calling people's bluffs, often using the specific phrase, "Name three."

But the real subject of today's lesson is how to see skills like this on the 5-second level.  And now that we have a specific example in hand, we can proceed to try to zoom in on the level of cognitive events that happen in 5 seconds or less.

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Rationality & Criminal Law: Some Questions

14 simplicio 20 June 2010 07:42AM

The following will explore a couple of areas in which I feel that the criminal justice system of many Western countries might be deficient, from the standpoint of rationality. I am very much interested to know your thoughts on these and other questions of the law, as far as they relate to rational considerations.

Moral Luck

Moral luck refers to the phenomenon in which behaviour by an agent is adjudged differently based on factors outside the agent's control.

Suppose that Alice and Yelena, on opposite ends of town, drive home drunk from the bar, and both dazedly speed through a red light, unaware of their surroundings. Yelena gets through nonetheless, but Alice hits a young pedestrian, killing him instantly. Alice is liable to be tried for manslaughter or some similar charge; Yelena, if she is caught, will only receive the drunk driving charge and lose her license.

Raymond, a day after finding out that his ex is now in a relationship with Pardip, accosts Pardip at his home and attempts to stab him in the chest; Pardip smashes a piece of crockery over Raymond's head, knocking him unconscious. Raymond is convicted of attempted murder, receiving typically 3-5 years chez nous (in Canada). If he had succeeded, he would have received a life sentence, with parole in 10-25 years.

Why should Alice be punished by the law and demonized by the public so much more than Yelena, when their actions were identical, differing only by the sheerest accident? Why should Raymond receive a lighter sentence for being an unsuccessful murderer?

Some prima facie plausible justifications:

  • Identical behaviour is hard to judge - perhaps Yelena was really keeping a better eye on the road than Alice; perhaps Raymond would have performed a non-fatal stabbing.
But in Yelena's case, the law is already blind to such things anyway. You don't get a lesser drunk driving charge if you can prove you're pretty good at driving drunk. In the case of Raymond, attempted murder already implies that the intent to kill must be proven, else the charge would have been dropped to assault or some such.
  • The law needs to crack down harder when there are actual victims, in order to provide the victims and families a sense of justice done.
This is understandable, but surely if we accept this argument, we could nonetheless satisfy the concerns above by punishing the morally lucky more severely, not punishing the morally unlucky less severely.
  • This could result in far too many serious, high-level trials.
This might be true as far as it goes; however, enforcing strong sentences on the morally lucky would certainly provide a stronger deterrent, which would provide a countervailing tendency to the above.

Trial by Jury; Trial by Judge

Those of us who like classic films may remember 12 Angry Men (1957) with Henry Fonda. This was a remarkably good film about a jury deliberating on the murder trial of a poor young man from a bad neighbourhood, accused of killing his father. It portrays the indifference (one juror wants to be out in time for the baseball game), prejudice and conformity of many of the jurors, and how this is overcome by one man of integrity who decides to insist on a thorough look through the evidence and testimony.

I do not wish to generalize from fictional examples; however, such factors are manifestly at play in real trials, in which Henry Fonda cannot necessarily be relied upon to save the day.

Komponisto has written on the Knox case, in which an Italian jury came to a very questionable (to put it mildly) conclusion based on the evidence presented to them; other examples will doubtless spring to mind (a famous one in this neck of the woods is the Stephen Truscott case - the evidence against Truscott being entirely circumstantial.

More information on trial by jury and its limitations may be found  here. Recently the UK has made some moves to trial by judge for certain cases, specifically fraud cases in which jury tampering is a problem.

The justifications cited for trial by jury typically include the egalitarian nature of the practice, in which it can be guaranteed that those making final legal decisions do not form a special class over and above the ordinary citizens whose lives they effect.

A heartening example of this was mentioned in Thomas Levenson's fascinating book  Newton and the Counterfeiter. Being sent to Newgate gaol was, infamously in the 17th and 18th centuries, an effective death sentence in and of itself; moreover, a surprisingly large number of crimes at this time were capital crimes (the counterfeiter whom Newton eventually convicted was hanged). In this climate of harsh punishment, juries typically only returned guilty verdicts either when evidence was extremely convincing or when the crime was especially heinous. Effectively, they counteracted the harshness of the legal system by upping the burden of proof for relatively minor crimes.

So juries sometimes provide a safeguard against abuse of justice by elites. However, is this price for democratizing justice too high, given the ease with which citizens naive about the Dark Arts may be manipulated? (Of course, judges are by no means perfect Bayesians either; however, I would expect them to be significantly less gullible.)

Are there any other systems that might be tried, besides these canonical two? What about the question of representation? Does the adversarial system, in which two sides are represented by advocates charged with defending their interests, conduce well to truth and justice, or is there a better alternative? For any alternatives you might consider: are they naive or savvy about human nature? What is the normative role of punishment, exactly?

How would the justice system look if LessWrong had to rewrite it from scratch?

Defeating Ugh Fields In Practice

65 Psychohistorian 19 June 2010 07:37PM

Unsurprisingly related to: Ugh fields.

If I had to choose a single piece of evidence off of which to argue that the rationality assumption of neoclassical economics is totally, irretrievably incorrect, it's this article about financial incentives and medication compliance. In short, offering people small cash incentives vastly improves their adherence to life-saving medical regimens. That's right. For a significant number of people, a small chance at winning $10-100 can be the difference between whether or not they stick to a regimen that has a very good chance of saving their life. This technique has even shown promise in getting drug addicts and psychiatric patients to adhere to their regimens, for as little as a $20 gift certificate. This problem, in the aggregate, is estimated to cost about 5% of total health care spending -$100 billion - and that may not properly account for the utility lost by those who are harmed beyond repair. To claim that people are making a reasoned decision between the payoffs of taking and not-taking their medication, and that they be persuaded to change their behaviour by a payoff of about $900 a year (or less), is to crush reality into a theory that cannot hold it. This is doubly true when you consider that some of these people were fairly affluent. 

A likely explanation of this detrimental irrationality is something close to an Ugh field. It must be miserable having a life-threatening illness. Being reminded of it by taking a pill every single day (or more frequently) is not pleasant. Then there's the question of whether you already took the pill. Because if you take it twice in one day, you'll end up in the hospital. And Heaven forfend your treatment involves needles. Thus, people avoid taking their medicine because the process becomes so unpleasant, even though they know they really should be taking it.

As this experiment shows, this serious problem has a simple and elegant solution: make taking their medicine fun. As one person in the article describes it, using a low-reward lottery made taking his meds "like a game;" he couldn't wait to check the dispenser to see if he'd won (and take his meds again). Instead of thinking about how they have some terrible condition, they get excited thinking about how they could be winning money. The Ugh field has been demolished, with the once-feared procedure now associated with a tried-and-true intermittent reward system. It also wouldn't surprise me the least if people who are unlikely to adhere to a medical regimen are the kind of people who really enjoy playing the lottery.

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Free copy of Feynman's autobiography for best corny rationalist joke

13 GreenRoot 04 April 2010 12:32AM

Portrait of Richard FeynmanI have an extra copy of Richard Feyman's autobiography, "Surely You're Joking, Mr. Feynman!": Aventures of a Curious Character, which I want to give away here.

This is one of two autobiographies (along with Ben Franklin's) to actually change my life.  I've seen it quoted often on LessWrong, as Feynman has a point of view on life that fits well with the ideas we explore here.  In addition to his rationalist side, Feynman also exhibited a wonderfully free sense of humor. Even when working at the Manhattan Project, he joked around and never took himself too seriously.  I think our community would benefit if the rationalism here were likewise leavened by some self-deprecating humor.

I will mail the autobiography, at my expense, to whomever posts the best corny rationalist joke in the comments below, as judged by karma voting.  Anything goes.  Here's a little inspirational prompting:

  • How many rationalists does it take to screw in a lightbulb? ...
  • Two rationalists walk into a bar. ...
  • You might be a rationalist if ...

Edit (April 12th): The winner of the corny rationalist joke contest is this one-liner by SilasBarta, which collected 17 net up-votes:

Rationalist pick-up line: "I would never cheat on you if and only if you would never cheat on me if and only if I would never cheat on you."

The runner-up (and my personal favorite) is this exchange by Bo102010, which collected 14 net up-votes.   The full comment thread for this one has an explanation and suggested refinements.

A rationalist walks into a bar with two bartenders. The rationalist asks "What's the best drink to get tonight?"

The first bartender says "The martini."

The second bartender says "The gin and tonic."

The first bartender repeats "The martini."

The second bartender repeats "The gin and tonic."

The first says again "The martini."

The second says again "The gin and tonic."

Then the first says "The gin and tonic."

The rationalist smiles and says, "I'm glad you could come to an agreement."

Thanks to everybody who contributed and voted on corny jokes.

Late Great Filter Is Not Bad News

14 Wei_Dai 04 April 2010 04:17AM

But I hope that our Mars probes will discover nothing. It would be good news if we find Mars to be completely sterile. Dead rocks and lifeless sands would lift my spirit.

Conversely, if we discovered traces of some simple extinct life form—some bacteria, some algae—it would be bad news. If we found fossils of something more advanced, perhaps something looking like the remnants of a trilobite or even the skeleton of a small mammal, it would be very bad news. The more complex the life we found, the more depressing the news of its existence would be. Scientifically interesting, certainly, but a bad omen for the future of the human race.

— Nick Bostrom, in Where Are They? Why I hope that the search for extraterrestrial life finds nothing

This post is a reply to Robin Hanson's recent OB post Very Bad News, as well as Nick Bostrom's 2008 paper quoted above, and assumes familiarity with Robin's Great Filter idea. (Robin's server for the Great Filter paper seems to be experiencing some kind of error. See here for a mirror.)

Suppose Omega appears and says to you:

(Scenario 1) I'm going to apply a great filter to humanity. You get to choose whether the filter is applied one minute from now, or in five years. When the designated time arrives, I'll throw a fair coin, and wipe out humanity if it lands heads. And oh, it's not the current you that gets to decide, but the version of you 4 years and 364 days from now. I'll predict his or her decision and act accordingly.

I hope it's not controversial that the current you should prefer a late filter, since (with probability .5) that gives you and everyone else five more years of life. What about the future version of you? Well, if he or she decides on the early filter, that would constitutes a time inconsistency. And for those who believe in multiverse/many-worlds theories, choosing the early filter shortens the lives of everyone in half of all universes/branches where a copy of you is making this decision, which doesn't seem like a good thing. It seems clear that, ignoring human deviations from ideal rationality, the right decision of the future you is to choose the late filter.

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The mathematical universe: the map that is the territory

68 ata 26 March 2010 09:26AM

This post is for people who are not familiar with the Level IV Multiverse/Ultimate Ensemble/Mathematical Universe Hypothesis, people who are not convinced that there’s any reason to believe it, and people to whom it appears believable or useful but not satisfactory as an actual explanation for anything.

I’ve found that while it’s fairly easy to understand what this idea asserts, it is more difficult to get to the point where it actually seems convincing and intuitively correct, until you independently invent it for yourself. Doing so can be fun, but for those who want to skip that part, I’ve tried to write this post as a kind of intuition pump (of the variety, I hope, that deserves the non-derogatory use of that term) with the goal of leading you along the same line of thinking that I followed, but in a few minutes rather than a few years.


Once upon a time, I was reading some Wikipedia articles on physics, clicking links aimlessly, when I happened upon a page then titled “Ultimate Ensemble”. It described a multiverse of all internally-consistent mathematical structures, thereby allegedly explaining our own universe — it’s mathematically possible, so it exists along with every other possible structure.

Now, I was certainly interested in the question it was attempting to answer. It’s one that most young aspiring deep thinkers (and many very successful deep thinkers) end up at eventually: why is there a universe at all? A friend of mine calls himself an agnostic because, he says, “Who created God?” and “What caused the Big Bang?” are the same question. Of course, they’re not quite the same, but the fundamental point is valid: although nothing happened “before” the Big Bang (as a more naïve version of this query might ask), saying that it caused the universe to exist still requires us to explain what brought about the laws and circumstances allowing the Big Bang to happen. There are some hypotheses that try to explain this universe in terms of a more general multiverse, but all of them seemed to lead to another question: “Okay, fine, then what caused that to be the case?”

The Ultimate Ensemble, although interesting, looked like yet another one of those non-explanations to me. “Alright, so every mathematical structure ‘exists’. Why? Where? If there are all these mathematical structures floating around in some multiverse, what are the laws of this multiverse, and what caused those laws? What’s the evidence for it?” It seemed like every explanation would lead to an infinite regress of multiverses to explain, or a stopsign like “God did it” or “it just exists because it exists and that’s the end of it” (I’ve seen that from several atheists trying to convince themselves or others that this is a non-issue) or “science can never know what lies beyond this point” or “here be dragons”. This was deeply vexing to my 15-year-old self, and after a completely secular upbringing, I suffered a mild bout of spirituality over the following year or so. Fortunately I made a full recovery, but I gave in and decided that Stephen Hawking was right that “Why does the universe bother to exist?” would remain permanently unanswerable.

Last year, I found myself thinking about this question again — but only after unexpectedly making my way back to it while thinking about the idea of an AI being conscious. And the path I took actually suggested an answer this time. 

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That Magical Click

58 Eliezer_Yudkowsky 20 January 2010 04:35PM

Followup toNormal Cryonics

Yesterday I spoke of that cryonics gathering I recently attended, where travel by young cryonicists was fully subsidized, leading to extremely different demographics from conventions of self-funded activists.  34% female, half of those in couples, many couples with kids - THAT HAD BEEN SIGNED UP FOR CRYONICS FROM BIRTH LIKE A GODDAMNED SANE CIVILIZATION WOULD REQUIRE - 25% computer industry, 25% scientists, 15% entertainment industry at a rough estimate, and in most ways seeming (for smart people) pretty damned normal.

Except for one thing.

During one conversation, I said something about there being no magic in our universe.

And an ordinary-seeming woman responded, "But there are still lots of things science doesn't understand, right?"

Sigh.  We all know how this conversation is going to go, right?

So I wearily replied with my usual, "If I'm ignorant about a phenomenon, that is a fact about my state of mind, not a fact about the phenomenon itself; a blank map does not correspond to a blank territory -"

"Oh," she interrupted excitedly, "so the concept of 'magic' isn't even consistent, then!"

Click.

She got it, just like that.

This was someone else's description of how she got involved in cryonics, as best I can remember it, and it was pretty much typical for the younger generation:

"When I was a very young girl, I was watching TV, and I saw something about cryonics, and it made sense to me - I didn't want to die - so I asked my mother about it.  She was very dismissive, but tried to explain what I'd seen; and we talked about some of the other things that can happen to you after you die, like burial or cremation, and it seemed to me like cryonics was better than that.  So my mother laughed and said that if I still felt that way when I was older, she wouldn't object.  Later, when I was older and signing up for cryonics, she objected."

Click.

It's... kinda frustrating, actually.

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Calibration for continuous quantities

26 Cyan 21 November 2009 04:53AM

Related to: Calibration fail, Test Your Calibration!

Around here, calibration is mostly approached on a discrete basis: for example, the Technical Explanation of Technical Explanations talks only about discrete distributions, and the commonly linked tests and surveys are either explicitly discrete or offer only coarsely binned probability assessments. For continuous distributions (or "smooth" distributions over discrete quantities like dates of historical events, dollar amounts on the order of hundreds of thousands, populations of countries, or any actual measurement of a continuous quantity), we can apply a finer-grained assessment of calibration.

The problem of assessing calibration for continuous quantities is that our distributions can have very dissimilar shapes, so there doesn't seem to be a common basis for comparing one to another. As an example, I'll give some subjective (i.e., withdrawn from my nether regions) distributions for the populations of two countries, Canada and Botswana. I live in Canada, so I have years of dimly remembered geography classes in elementary school and high school to inform my guess. In the case of Botswana, I have only my impressions of the nation from Alexander McCall Smith's excellent No. 1 Ladies' Detective Agency series and my general knowledge of Africa.

For Canada's population, I'll set my distribution to be a normal distribution centered at 32 million with a standard deviation of 2 million. For Botswana's population, my initial gut feeling is that it is a nation of about 2 million people. I'll put 50% of my probability mass between 1 and 2 million, and the other 50% of my probability mass between 2 million and 10 million. Because I think that values closer to 2 million are more plausible than values at the extremes, I'll make each chunk of 50% mass a right-angle triangular distribution. Here are plots of the probability densities:

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When Willpower Attacks

17 jimrandomh 03 October 2009 03:36AM

Less Wrong has held many discussions of willpower. All of them have focused on the cases where willpower fails, and its failure causes harm, such as procrastination, overeating and addiction. Collectively, we call these behaviors akrasia. Akrasia is any behavior that we believe is harmful, but do anyways due to a lack of willpower. Akrasia, however, represents only a small subset of the cases in which willpower fails, and focusing on it too much creates an availability bias that skews our perception of what willpower is, how it works and how much of it is desireable. To counter this bias, I present here some common special cases where strong willpower is harmful or even fatal.

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